I'm currently on 5.0.1 and on JB; music, pictures and other files do not matter to me (they can be easily backed up).
However my question is on my contacts, notes and reminders. Everytime I update an IOS version, i-plug it to pc, restore to higher version (everything is deleted).
Is there anyway I can back up my contacts and notes ? everytime I do update I do re-type all my contacts